An integrated security-aware job scheduling strategy for large-scale computational grids

All existing fault-tolerance job scheduling algorithms for computational grids were proposed under the assumption that all sites apply the same fault-tolerance strategy. They all ignored that each grid site may have its own fault-tolerance strategy because each site is itself an autonomous domain. In fact, it is very common that there are multiple fault-tolerance strategies adopted at the same time in a large-scale computational grid. Various fault-tolerance strategies may have different hardware and software requirements. For instance, if a grid site employs the job checkpointing mechanism, each computation node must have the following ability. Periodically, the computational node transmits the transient state of the job execution to the server. If a job fails, it will migrate to another computational node and resume from the last stored checkpoint. Therefore, in this paper we propose a genetic algorithm for job scheduling to address the heterogeneity of fault-tolerance mechanisms problem in a computational grid. We assume that the system supports four kinds fault-tolerance mechanisms, including the job retry, the job migration without checkpointing, the job migration with checkpointing, and the job replication mechanisms. Because each fault-tolerance mechanism has different requirements for gene encoding, we also propose a new chromosome encoding approach to integrate the four kinds of mechanisms in a chromosome. The risk nature of the grid environment is also taken into account in the algorithm. The risk relationship between jobs and nodes are defined by the security demand and the trust level. Simulation results show that our algorithm has shorter makespan and more excellent efficiencies on improving the job failure rate than the Min–Min and sufferage algorithms.     

An efficient memetic algorithm for solving the job shop scheduling problem

The job shop scheduling problem (JSP) is well known as one of the most complicated combinatorial optimization problems, and it is a NP-hard problem. Memetic algorithm (MA) which combines the global search and local search is a hybrid evolutionary algorithm. In this paper, an efficient MA with a novel local search is proposed to solve the JSP. Within the local search, a systematic change of the neighborhood is carried out to avoid trapping into local optimal. And two neighborhood structures are designed by exchanging and inserting based on the critical path. The objective of minimizing makespan is considered while satisfying a number of hard constraints. The computational results obtained in experiments demonstrate that the efficiency of the proposed MA is significantly superior to the other reported approaches in the literature.     

Adaptive energy efficient scheduling in Peer-to-Peer desktop grids

We address non-preemptive scheduling problems on heterogeneous P2P grids, where resources are changing over time, and scheduling decisions are free from information of application characteristics. We consider a scheduling with task replications to overcome possible bad resource allocation in presence of uncertainty, and ensure good performance. We analyze the energy consumption of job allocation strategies exploring the replication thresholds, and dynamic component deactivation. The main idea of our approach is to set replication thresholds, and dynamically adapt them to cope with different objective preferences, workloads, and Grid properties. We compare three groups of strategies: knowledge-free, speed-aware, and power-aware. In order to provide good performance and minimize energy consumption, first, we perform a joint analysis of two metrics considering their degradation in performance. Then, we provide two-objective optimization analysis that is not restricted to find a unique solution, but the Pareto optimal set. Based on these results, we use a Set Coverage metric for assessing the performance of our strategies and compare twenty algorithms in terms of Pareto dominance. A case study is given, and corresponding results indicate that two replicas for knowledge-free algorithms, and one replica for speed-aware algorithms provide the best energy and performance trade-offs in the scheduling. They perform well in different scenarios with a variety of workloads and grid configurations.     

一种快速网格任务调度策略

网格任务调度目标有很多,如用户要求任务轮转时间短、花费代价小,而资源提供者希望资源利用率高等,这些目标相互冲突,因此网格任务调度不仅是一个NP难问题,而且是一个多目标优化问题.本文根据网格环境下任务的时间相关性特点,对传统蚁群算法进行了改进,提出了一种快速网格任务调度算法.该算法不仅解决了网格调度中多目标优化问题,而且依据任务调度历史信息生成蚁群算法的初始信息素分布,提高了蚁群算法的求解速度.     

A hybrid genetic algorithm for the job shop scheduling problems

The Job Shop Scheduling Problem (JSSP) is one of the most general and difficult of all traditional scheduling problems. The goal of this research is to develop an efficient scheduling method based on genetic algorithm to address JSSP. We design a scheduling method based on Single Genetic Algorithm (SGA) and Parallel Genetic Algorithm (PGA). In the scheduling method, the representation, which encodes the job number, is made to be always feasible, the initial population is generated through integrating representation and G&T algorithm, the new genetic operators and selection method are designed to better transmit the temporal relationships in the chromosome, and island model PGA are proposed. The scheduling methods based on genetic algorithm are tested on five standard benchmark JSSP. The results are compared with other proposed approaches. Compared to traditional genetic algorithm, the proposed approach yields significant improvement in solution quality. The superior results indicate the successful incorporation of a method to generate initial population into the genetic operators.     

A Bee Colony based optimization approach for simultaneous job scheduling and data replication in grid environments

This paper presents a novel Bee Colony based optimization algorithm, named Job Data Scheduling using Bee Colony (JDS-BC). JDS-BC consists of two collaborating mechanisms to efficiently schedule jobs onto computational nodes and replicate datafiles on storage nodes in a system so that the two independent, and in many cases conflicting, objectives (i.e., makespan and total datafile transfer time) of such heterogeneous systems are concurrently minimized. Three benchmarks – varying from small- to large-sized instances – are used to test the performance of JDS-BC. Results are compared against other algorithms to show JDS-BC's superiority under different operating scenarios. These results also provide invaluable insights into data-centric job scheduling for grid environments.     

An improved approximation algorithm for single machine scheduling with job delivery

In single machine scheduling with release times and job delivery, jobs are processed on a single machine and then delivered by a capacitated vehicle to a single customer. Only one vehicle is employed to deliver these jobs. The vehicle can deliver at most c jobs in a shipment. The delivery completion time of a job is defined as the time in which the delivery batch containing the job is delivered to the customer and the vehicle returns to the machine. The objective is to minimize the makespan, i.e., the maximum delivery completion time of the jobs. We provide an approximation algorithm for this problem which is better than that given in the literature, improving the performance ratio from 5/3 to 3/2.     

An effective asexual genetic algorithm for solving the job shop scheduling problem

By using the notion of elite pool, this paper presents an effective asexual genetic algorithm for solving the job shop scheduling problem. Based on mutation operations, the algorithm selectively picks the solution with the highest quality from the pool and after its modification, it can replace the solution with the lowest quality with such a modified solution. The elite pool is initially filled with a number of non-delay schedules, and then, in each iteration, the best solution of the elite pool is removed and mutated in a biased fashion through running a limited tabu search procedure. A decision strategy which balances exploitation versus exploration determines (i) whether any intermediate solution along the run of tabu search should join the elite pool, and (ii) whether upon joining a new solution to the pool, the worst solution should leave the pool. The genetic algorithm procedure is repeated until either a time limit is reached or the elite pool becomes empty. The results of extensive computational experiments on the benchmark instances indicate that the success of the procedure significantly depends on the employed mechanism of updating the elite pool. In these experiments, the optimal value of the well-known 10 × 10 instance, ft10, is obtained in 0.06 s. Moreover, for larger problems, solutions with the precision of less than one percent from the best known solutions are achieved within several seconds.     

Toward balanced and sustainable job scheduling for production supercomputers

Job scheduling on production supercomputers is complicated by diverse demands of system administrators and amorphous characteristics of workloads. Specifically, various scheduling goals such as queuing efficiency and system utilization are usually conflicting and thus need to be balanced. Also, changing workload characteristics often impact the effectiveness of the deployed scheduling policies. Thus it is challenging to design a versatile scheduling policy that is effective in all circumstances. In this paper, we propose a novel job scheduling strategy to balance diverse scheduling goals and mitigate the impact of workload characteristics. First, we introduce metric-aware scheduling, which enables the scheduler to balance competing scheduling goals represented by different metrics such as job waiting time, fairness, and system utilization. Second, we design a scheme to dynamically adjust scheduling policies based on feedback information of monitored metrics at runtime. We evaluate our design using real workloads from supercomputer centers. The results demonstrate that our scheduling mechanism can significantly improve system performance in a balanced, sustainable fashion.     

An effective ant colony optimization algorithm for multi-objective job-shop scheduling with equal-size lot-splitting

This paper proposes several novel hybrid ant colony optimization (ACO)-based algorithms to resolve multi-objective job-shop scheduling problem with equal-size lot splitting. The main issue discussed in this paper is lot-splitting of jobs and tradeoff between lot-splitting costs and makespan. One of the disadvantages of ACO is its uncertainty on time of convergence. In order to enrich search patterns of ACO and improve its performance, five enhancements are made in the proposed algorithms including: A new type of pheromone and greedy heuristic function; Three new functions of state transition rules; A nimble local search algorithm for the improvements of solution quality; Mutation mechanism for divisive searching; A particle swarm optimization (PSO)-based algorithm for adaptive tuning of parameters. The objectives that are used to measure the quality of the generated schedules are weighted-sum of makespan, tardiness of jobs and lot-splitting cost. The developed algorithms are analyzed extensively on real-world data obtained from a printing company and simulated data. A mathematical programming model is developed and paired-samples t-tests are performed between obtained solutions of mathematical programming model and proposed algorithms in order to verify effectiveness of proposed algorithms.     

A new hybrid genetic algorithm for job shop scheduling problem

Job shop scheduling problem is a typical NP-hard problem. To solve the job shop scheduling problem more effectively, some genetic operators were designed in this paper. In order to increase the diversity of the population, a mixed selection operator based on the fitness value and the concentration value was given. To make full use of the characteristics of the problem itself, new crossover operator based on the machine and mutation operator based on the critical path were specifically designed. To find the critical path, a new algorithm to find the critical path from schedule was presented. Furthermore, a local search operator was designed, which can improve the local search ability of GA greatly. Based on all these, a hybrid genetic algorithm was proposed and its convergence was proved. The computer simulations were made on a set of benchmark problems and the results demonstrated the effectiveness of the proposed algorithm.     

Multihybrid job scheduling for fault-tolerant distributed computing in policy-constrained resource networks

Unpredictable fluctuations in resource availability often lead to rescheduling decisions that sacrifice a success rate of job completion in batch job scheduling. To overcome this limitation, we consider the problem of assigning a set of sequential batch jobs with demands to a set of resources with constraints such as heterogeneous rescheduling policies and capabilities. The ultimate goal is to find an optimal allocation such that performance benefits in terms of makespan and utilization are maximized according to the principle of Pareto optimality, while maintaining the job failure rate close to an acceptably low bound. To this end, we formulate a multihybrid policy decision problem (MPDP) on the primary-backup fault tolerance model and theoretically show its NP-completeness. The main contribution is to prove that our multihybrid job scheduling (MJS) scheme confidently guarantees the fault-tolerant performance by adaptively combining jobs and resources with different rescheduling policies in MPDP. Furthermore, we demonstrate that the proposed MJS scheme outperforms the five rescheduling heuristics in solution quality, searching adaptability and time efficiency by conducting a set of extensive simulations under various scheduling conditions.     

求解有限产能作业车间调度的改进蚂蚁算法

通过对有限产能车间调度问题的分析,提出了基于蚂蚁算法求解该问题的方法。在模型的构建中增加了成本和机器负荷约束。通过产品的BOM表采用蚂蚁算法搜寻节点,做各阶层工序安排,将各阶层工序安排组合成一完整解。对蚂蚁算法进行了改进,在基本蚂蚁算法的基础上,通过修改信息素局域更新规则和全局更新规则,引入自适应信息素挥发系数来提高算法的收敛速度和全局最优解搜索能力。算例分析表明,蚂蚁的正向反馈及探索功能对求解较大工件数的生产计划非常有效。而且在有限产能的环境中根据产能负荷状况产生不同的外包组合,将满足交货期的各种外包组合成本做敏感性分析,供决策者参考。     

Ant colony optimization combined with taboo search for the job shop scheduling problem

In this paper, we present a hybrid algorithm combining ant colony optimization algorithm with the taboo search algorithm for the classical job shop scheduling problem. Instead of using the conventional construction approach to construct feasible schedules, the proposed ant colony optimization algorithm employs a novel decomposition method inspired by the shifting bottleneck procedure, and a mechanism of occasional reoptimizations of partial schedules. Besides, a taboo search algorithm is embedded to improve the solution quality. We run the proposed algorithm on 101 benchmark instances and obtain competitive results and a new best upper bound for one open benchmark instance is found.     

基于免疫蚂蚁算法的Job-shop调度问题

描述了作业调度问题，借鉴生物免疫机理提出了求解车间调度问题的免疫蚁群算法，该方法在蚂蚁搜索程中，运用免疫机理提取疫苗，并对进化种群进行免疫操作，从而有效地抑制了蚁群算法的“早熟”和搜索效率低下的问题，显著地提高了蚁群算法对全局最优解的搜索能力和收敛速度，给出了免疫蚁群算法的具体步骤，并对算法进行了实例验证。     

An incentive-based heuristic job scheduling algorithm for utility grids

Job scheduling in utility grids should take into account the incentives for both grid users and resource providers. However, most of existing studies on job scheduling in utility grids only address the incentive for one party, i.e., either the users or the resource providers. Very few studies on job scheduling in utility grids consider incentives for both parties, in which the cost, one of the most attractive incentives for users, is not addressed. In this paper, we study the job scheduling in utility grid by optimizing the incentives for both parties. We propose a multi-objective optimization approach, i.e., maximizing the successful execution rate of jobs and minimizing the combined cost (incentives for grid users), and minimizing the fairness deviation of profits (incentive for resource providers). The proposed multi-objective optimization approach could offer sufficient incentives for the two parties to stay and play in the utility grid. A heuristic scheduling algorithm called Cost-Greedy Price-Adjusting (CGPA) algorithm is developed to optimize the incentives for both parties. Simulation results show that the CGPA algorithm is effective and could lead to higher successful execution rate, lower combined cost and lower fairness deviation compared with some popular algorithms in most cases.     

云计算环境下基于遗传蚁群算法的任务调度研究

对云计算中任务调度进行了研究,针对云计算的编程模型框架,提出一种融合遗传算法与蚁群算法的混合调度算法。在该求解方法中,遗传算法采用任务-资源的间接编码方式,每条染色体代表一种具体调度方案;选取任务平均完成时间作为适应度函数,再利用遗传算法生成的优化解,初始化蚁群信息素分布。既克服了蚁群算法初期信息素缺乏,导致求解速度慢的问题,又充分利用遗传算法的快速随机全局搜索能力和蚁群算法能模拟资源负载情况的优势。通过仿真实验将该算法和遗传算法进行比较,实验结果表明,该算法是一种云计算环境下有效的任务调度算法。     

基于改进蚁群算法的云计算任务调度

利用云中资源进行高效任务调度是保证云计算系统可靠运行的关键问题。提出一种基于改进蚁群优化算法的任务调度方法。算法采用蚂蚁系统的伪随机比例规则进行寻优,防止算法过快收敛到局部最优解,同时结合排序蚂蚁系统和最大最小蚂蚁系统的设计思想完成信息素更新,有效求解优化问题。实验结果显示,该算法具有很好的寻优能力,提高了云资源的利用率。     

An SCP-based heuristic approach for scheduling distributed data-intensive applications on global grids

Data-intensive Grid applications need access to large data sets that may each be replicated on different resources. Minimizing the overhead of transferring these data sets to the resources where the applications are executed requires that appropriate computational and data resources be selected. In this paper, we consider the problem of scheduling an application composed of a set of independent tasks, each of which requires multiple data sets that are each replicated on multiple resources. We break this problem into two parts: one, to match each task (or job) to one compute resource for executing the job and one storage resource each for accessing each data set required by the job and two, to assign the set of tasks to the selected resources. We model the first part as an instance of the well-known Set Covering Problem (SCP) and apply a known heuristic for SCP to match jobs to resources. The second part is tackled by extending existing MinMin and Sufferage algorithms to schedule the set of distributed data-intensive tasks. Through simulation, we experimentally compare the SCP-based matching heuristic to others in conjunction with the task scheduling algorithms and present the results.     

求解差异工件批调度问题的改进型蚁群算法

针对最小化制造跨度的差异工件尺寸单批处理机调度问题,通过将其转化为最小化浪费空间的问题,采用候选集策略构建分批以减少搜索空间,利用基于浪费空间的启发式更新信息素,提出一种改进的最大最小蚁群算法。此外,在算法中还引入了一种局部优化策略,以进一步提高算法的性能。仿真实验结果表明,所提出的算法优于其他几种已有算法,验证了所提出算法的有效性和鲁棒性。